As technology progresses, wireless communication protocols demand increasing rates of data transfer. Therefore, increasingly efficient methods of data encoding and processing are often required. Some wireless systems incorporate dual receiver architectures to simultaneously process data from two different data streams. Such approaches may double data rates when compared with existing architectures. For example, an Enhanced Data Rates for Global Evolution (EDGE) Evolution protocol is a multiple radio frequency (RF) channel protocol. Two data streams are transmitted to a dual receiver, such that each data stream has its own set of radio frequency (RF) channels. Transmission may alternate between the two data steams as each data stream switches its RF channel, such that only one data stream is transmitted at a time.
For example, a first data stream is transmitted on one of a first set of RF channels followed by a second data stream transmitted on one of a second set of RF channels. Then, the first data stream is transmitted on another of the first set of RF channels followed by the second data stream transmitted on another of the second set of RF channels, and so on. On the receive side, while the first data stream is being received by a first side of the dual receiver, a second side of the dual receiver is switching RF channels in preparation to receive the second data stream. Then, while the second data stream is being received by the second side of the dual receiver, a first side of the dual receiver is switching RF channels in preparation to receive the first data stream. Since data is being received by one side of the dual receiver while the other side of the dual receiver is switching RF channels, this approach allows continuous reception of data.
Each side of the dual receiver may have its own local oscillator for selecting the appropriate RF channel, and since each data stream has its own set of RF channels, it may be possible for one side of the dual receiver to be receiving on one RF channel while the other side of the dual receiver is switching to the same or an adjacent RF channel. Therefore, both local oscillators may be tuned to the same or nearly the same frequency. Since both local oscillators may be provided by the same semiconductor die or by a common module, circuit parasitics may introduce noise or instability into the local oscillators that would not be present when the local oscillators are tuned to different frequencies. The noise or instability may de-sensitize either of both sides of the dual receiver, thereby reducing the effective sensitivity of the dual receiver. Thus, there is a need to reduce the noise or instability associated with local oscillators tuned to about the same frequency.